Copolymers of vinyl chloride



Unite poration of Delaware No Drawing. Filed July 31, 1959, Ser. No.830,699

8 Claims. ((31. 260-:-87.5)

The present invention relates to novel vinyl chloride interpolymers andto methods for preparing same.

Vinyl chloride homopolymers are Widely employed as a surface coatingresin, as a wire insulation resin, and for diverse other purposes. Arelatively recent development in the art has been the employment ofvinyl chloride polymer insulated wires as underground electrical cables.The insulation on such underground cables must be able to withstandsevere physical punishment and for maximum utility requires vinylchloride polymers having physical properties superior to those of manyof the presently commerically available vinyl chloride homopolymers. Inparticular, this development requires vinyl chloride polymers having ahigh tensile strength, a high 100% modulus and a high crush-resistance.

It is known that the physical properties of vinyl chloride homopolymerssuch as tensile strength, 100% modulus and crush-resistance can beimproved by preparing the polymer under such conditions that highermolecular weights are obtained. To obtain such higher molecular Weightsit has heretofore been necessary to lower the polymerization temperatureor to reduce the concentration of free radial generating polymerizationinitiator employed or both. Such modifications of the polymerizationprocess increase the cost of preparing vinyl chloride homopolymers inthat they lower the rate of polymerization and concomitantly theproductive capacity of the equipment in which the polymer is prepared.

A method sometimes proposed for increasing the molecular weight ofpolymers is to incorporate a small quantity of a cross-linking monomer,i.e., a monomer containing two or more non-conjugated terminal ethylenicgroups, in the monomer charge. This method has been used successfullywith some polymer systems, but it is not generally applicable to thepreparation of vinyl chloride polymers of high molecular weight. Inparticular, it is difficult to find cross-linking monomers which willinterpolymerize with vinyl chloride at satisfactory rates. Moreover,where interpolymers can be formed, they tend to be quite heterogeneousin composition and in most cases the interpolymer contains a highlygelled fraction which is insoluble in most solvents for the vinylchloride interpolymer. Such interpolymers, because of theirheterogeneity and insoluble gel fraction, can not be employed in surfacecoating compositions.

It is an object of this invention to provide vinyl chloride polymershaving improved physical properties.

Another object of this invention is to provide a process for preparingvinyl chloride polymers of improved physical properties, which processcan be carried out in conventional polymerization equipment.

A further object of this invention is to provide a vinyl chloridepolymerization process which, with no sacrifice in the rate ofpolymerization, yields vinyl chloride polymers of improved physicalproperties.

Other objects and advantages of this invention will-be apparent from thefollowing detailed description thereof.

It has been discovered that vinyl chloride polymers of improved physicalproperties, as compared with vinyl chloride homopolymers prepared underotherwise identical conditions, can be obtained by interpolymerizingminute but critical quantities of a po1y-N-allyl substituted amine withvinyl chloride. Suchimproved vinyl chloride States Patent proved as themolecular weight of the vinyl chloride polymer is increased. This istrue not only for vinyl chloride polymers per se, but also forformulated vinyl chloride polymer compositions containing plasticizers,pigments, fillers and other conventional polymer compoundingingredients. Since the Precision of molecular weight determinations ismuch higher than the precision of determinations of tensile strength,modulus and crushresistance, the comparison of polymer properties in thesubsequent examples is based primarily upon polymer molecular weights,such molecular weights being expressed in terms of the specificviscosities of the polymers. All of the specific viscosities reportedherein are determined on 0.4 weight percent solutions of the polymer incyclohexanone at 25 i0.05 C. The precision of the reported values is10.002. The formula employed for calculating specific viscosities is setforth below:

Specific y golution viscositysolvent. viscosity Solvent viscosity Thefollowing examples are set forth to illustrate more clearly theprinciple and practice of this invention to those skilled in the art.All parts are by weight.

EXAMPLE I Part A A vinyl chloride homopolymer is prepared in a stirredautoclave employing the suspension polymerization system set forthbelow.

Equimolar interpolymer of vinyl acetate and maleic anhydride.

, The polymerization is carried out at 51 C. and is completed in about16 hours. The vinyl chloride homopolymer has a specific viscosity of0.51.

Part B 1 Part C The vinyl chloride-diallylamine interpolymer of Part Bis compounded into the wire coating formulation set forth below.

Component: Parts by weight Resin 100 Di(2-e"ohylhexyl)phthalate 42Secondary plastieizer 1 22 1 Hydrocarbon type.

, ,3 Clay 20 Calcium carbonate 15 Stabilizer 8 Lubricant 1 The resultingformulation has a tensile strength of about 2600 psi. and 100% modulusof about 1800 p.s.i. By wayof contrast, when the vinyl chloridehomopolymer of Example I, Part A, is substituted for the vinylchloride-diallylamine interpolymer, the resulting formulation hastensile strength and 100% modulus values approximately 100 points lower.

EXAMPLES Il-V Example I, Part B, is repeated except that thediallylamine contained in the polymerization system is replaced with,respectively, diallylaniline, N,N'-diallylpiperazine, dimethallylamineand N-methyldiallylamine. "Ilhe physical properties of the resultinginterpolymerscorrespond to those of the interpolymer obtained in ExampleI,- Part B.

EXAMPLE VI An interpolymer, consisting of 99.97 weight percent of vinylchloride and 0.03 weight percent of triallylamine is prepared by theprocedure of Example I, Part B, and has a specific viscosity of about0.60.

EXAMPLES VII-XI Five vinyl chloride-diallylamine interpolymerscontaining varying quantities of diallylamine are prepared underidentical polymerization conditions following the procedure of ExampleI, Part B. The composition of the interpolymers and the specificviscosities thereof are set forth in Table I.

TABLE I As seen from the above table, each of the inter-polymerscontaining diallylamine has a higher specific viscosity than the controlvinyl chloride homopolymer. Each of the diallyarnine containinginterpolymers also has a higher tensile strength and 100% modulus thanthe control vinyl chloride homopolymer. In addition, each of theinterpolymers is free of gels and is completely soluble in such solventsas cyclo'hexanone and nitrobenzene. Accordingly, the interpolymers arewell suited for use in paints and other surface coating compositions.

, The interpolymers of this invention are binary interpolymersconsisting of vinyl chloride and a poly-N-allyl substituted amine, whichfor the sake of brevity will sometimes be referred to simply as theallylamine. The allylamines which can be employed in the practice ofthis invention can be aliphatic, aromatic or heterocyclic in nature andare characterized by (1) containing at least one amino group, (2)havingZ or 3 hydrogen atoms of the amino groups mentioned in (1)replaced with an allyl 4 cal methods that are known in the art and manyof these compounds are commercially available.

The proportions of vinyl chloride and allylamine included in theinterpolymers will depend upon the number of allyl (or methallyl) groupsincluded in the allylamine. When the allyla-mine contains 2 allyl (ormethallyl) groups, the interpolymer will consist of 99.70- 9999 andpreferably 99.85-99.98 weight percent of vinyl chloride and,correspondingly, 0.30-0.01 and preferably 0.15-0.02 weight percent ofthe allylamine. When the allylamine contains 3 allyl (or methallyl)groups, the interpolymer will consist of 99.95-99.997 and preferably99.96-99.995 weight percent of vinyl chloride and, correspondingly,0.05-0.003 and preferably 0.04-0.005 weight percent of the allylamine.

The interpolymers of the invention are preferably prepared by thewell-known suspension polymerization process inwhich the monomers aredispersed as small droplets in Water and polymerized therein. Although awater-soluble interpolymer of vinyl acetate and maleic anhydride hasbeen employed as the suspending agent in the examples herein presented,other known suspending agents such as gelatine, protective colloids,etc. may be employed if desired. The polymerizations are carried out attemperatures in the range of 30-70 C. in the presence of free radicalgenerating polymerization initiators such as lauroyl peroxide, benzoylperoxide, etc.

The interpolymers of this invention have higher molecular weights andbetter physical properties than corresponding vinyl chloridehomopolymers prepared under identical polymerizationconditions. Thus,the process of this invention makes possible the attainment of asuperior product at no increase in cost. Alternatively, interpolymers ofthis invention having equivalent physical properties to vinyl chloridehomopolymers can be prepared at higher polymerization temperatures.Polymerizing the inter-polymers at higher temperatures increases therate of polymerization and raises the productive capacity of thepolymerization vessel in which the reaction is carried out- Thus, theinterpolymers of this invention make possible the attainment of a higherproductive capacity per unit of capital investment. In general, theproductive capacity of a polymerization vessel for the inter-polymers ofthis invention is approximately 30% higher than the productive capacityof the same vessel for a vinyl chloride homopolymer, both of saidpolymers being polymerized under conditions which give identicalmolecular Weights.

The interpolymers of this invention may be used interchangeably withvinyl chloride homopolymers in virtually all industrial applications.The interpolymers are particularly suitable for use in the insulation ofelectric Wire and particularly for electric Wire that is to be employedas underground cable.

The above descriptions and particularly the examples are set forth byway of illustration only. Many other variations and modificationsthereof will be obvious to those skilled in the art and can be madeWithout departing from the spirit and scope of the invention hereindisclosed.

What is claimed is:

1. A resinous interpo-lymer of monomers consisting of 99.85-99.98 weightpercent of vinyl chloride and, correspondingly, 0.15-0.02 Weight percentof diallylamine.

2. A resinous interpolymer of monomers consisting of 99.85-99.98 weightpercent of vinyl chloride and, correspondingly, 0.15-0.02 weight percentof diallylaniline.

3. A resinous interpolymer of monomers consisting of 99.85-99.98 weightpercent of vinyl chloride and, correspondingly, 0.15-0.02 Weight percentof N,N-diallylpiperazine. i

4. A resinous interpolymer of a binary mixture of monomers consisting ofvinyl chloride and a poly-N-allyl substituted amine selected from thegroup consisting of diallylamine, diallylaniline,N,N'-diallylpiperazine, di-

methal-lylamine, N-methyldiallylamine, triallylarnine, N,-N-diallyletnylene diamine, N,N-diallyl ethylene diamine, N,N',N-triallyltriethylene diamine, N,N,N-triallyl-pphenylene idiamine anddimethallylethanolamine; said monomer mixture consisting of 99.70-99.99weight percent of vinyl chloride and, correspondingly, 0.30-0.01 Weightpercent of the poly-N-allyl substituted amine when thepoly-N-allylsubstituted amine contains 2 polymerizable terminalethylenic groups; said monomer mixture consisting of 99.95-99.997 weightpercent of vinyl chloride and, correspondingly, 0.05-0.003 Weightpercent of the poly-N-allyl substituted amine When the poly-N-allylsubstituted amine contains 3 polymerizable terminal ethylenic groups.

5. A resinous interpolymer of a binary mixture of monomers consisting ofvinyl chloride and a poly-N-allyl substituted amine selected from thegroup consisting of diallylamine, diallylaniline, N,N-diallylpiperazine,dimethallylamine, N-methyldiallylamine, triallylamine, N,N-dia1lylethylene diamine, N,N-diallyl ethylene diamine, N,N,N"-triallyltriethylene diamine, N,N,N triallyl-p-phenylene diamine anddimethallylethanolamine; said monomer mixture consisting of 99.85-99.98Weight percent of vinyl" chloride and, correspondingly, 0.15-0.02 weightpercent of the poly-N-allyl substituted amine when the poly-N-allylsubstituted amine contains 2 polymerizable terminal ethylenic groups;said monomer mixture consisting of 99.96-99.995 weight percent of vinylchloride and, correspondingly, 0.04-0.005 weight percent of thepoly-N-allyl substituted amine when the poly-N-allyl substituted aminecontains 3 polymerizable terminal ethylenic groups.

6. An insulated electric Wire comprising an electrical conductorcarrying an insulating coating of a resinous interpolymer of a binarymixture of monomers consisting of vinyl chloride and a poly-N-allylsubstituted amine selected from the group consisting of diallylamine,diallylaniline, N,N-diallylpiperazine, dimethallylamine, N-methyldiallylamine, triallylamine, N,N-diallyl ethylene diamine,N,N-diallyl ethylene diamine, N,NN-triallyl triethylene diamine,N,N,N-trial1y1-p-phenylene diamine and dimethallylethanolamine; saidmonomer mixture consisting of 99.70-99.99 weight percent of vinylchloride and, correspondingly, 0.30-0.01 weight percent of thepoly-N-allyl substituted amine when the poly-N-allyl substituted aminecontains 2 polymerizable terminal ethylenic groups; said monomer mixtureconsisting of 99.95- 99.997 weight percent of vinyl chloride and,correspondingly, 0.05-0.003 weight percent of the poly-N-allylsubstituted amine when the poly-N-allyl substituted amine contains 3polymerizable terminal ethylenic groups.

7. A suspension polymerization process for preparing a resinousinterpolymer of a monomer mixture consisting solely of vinyl chlorideand a poly-N-allyl substituted amine, which process comprises dispersingthe monomers as droplets in an aqueous medium containing therein asuspending agent and polymerizing the monomers at a temperature of 30-70C. in the presence of a free radical generating polymerizationinitiator; said poly-N-allyl substituted amine being selected from thegroup consisting of diallylamine, diallylaniline, N,N-diallylpiperazine,dimethallylamine, N-methyldiallylamine, triallylarnine,

-N,N-diallyl ethylene diamine, N,N-di allyl ethylene diamine,N,N',N-triallyl triethylene diamine, N,N,N'-triallyl-p-phenylene diamineand dimethallylethanolamine; said monomer mixture consisting of99.70-99.99 weight percent of vinyl chloride and, correspondingly,0.30-0.01 weight percent of the poly-N-allyl substituted amine when thepoly-N-allyl substituted amine contains 2 polymerizable terminalethylenic groups; said monomer mixture consisting of 99.95-99.997 weightpercent of vinyl chloride and, correspondingly, 0.05-0.003 weightpercent of the poly-N-allyl substituted amine when the poly-N-allylsubstituted amine contains 3 polymerizable terminal ethylenic groups.

8. A suspension polymerization process for preparing a resinousinterpolymer of a monomer mixture consisting solely of vinyl chlorideand a poly-N-allyl substituted amine, which process comprises dispersingthe monomers as droplets in an aqueous medium containing therein asuspending agent and polymerizing the monomers at a temperature of 30-70C. in the presence of a free radical generating polymerizationinitiator; said poly-N-allyl substituted amine being selected from thegroup consisting of diallylamine, diallylaniline, N,N-diallylpiperazine,dimethallylamine, N-methyldiallylamine, triallylamine, N,N-diallylethylene diamine, N,N'-diallyl ethylene diamine, N,N',N"-triallyltriethylene diamine, N,N,N- triallyl-p-phenylene diamine anddimethallylethanolamine; said monomer mixture consisting of 99.85-99.98weight percent of vinyl chloride and, correspondingly, 0.15-0.02 weightpercent of the poly-N-allyl substituted amine when the poly-N-allylsubstituted amine contains 2 polymerizable terminal ethylenic groups;said monomer mixture consisting of 99.96-99.995 Weight percent of vinylchloride and, correspondingly, 0.04-0.005 weight percent of the,poly-N-allyl substituted amine when the poly-N-allyl substituted aminecontains 3 polymerizable terminal ethylenic groups.

References Cited in the file of this patent UNITED STATES PATENTS2,712,004 Thomas June 28, 1955

6. AN INSULATED ELECTRIC WIRE COMPRISING AN ELECTRICAL CONDUCTORCARRYING AN INSULATING COATING OF A RESINOUS INTERPOLYMER OF A BINARYMIXTURE OF MONOMERS CONSISTING OF VINYL CHLORIDE AND A POLY-N-ALLYLSUBSTITUTED AMINE SELECTED FROM THE GROUP CONSISTING OF DIALLYLAMINE,DIALLYLANILINE, N,N''-DIALLYLPIPERAZINE, DIMETHYALLYLAMINE,NMETHYLDIALLYLAMINE, TRIALLYLAMINE, N,N-DIALLY ETHYLENE DIAMINE,N,N''-DIALLY ETHYLENE DIAMINE, N,N''N"-TRIALLYL TRIETHYLENE DIAMINE,N,N,N''-TRIALLY-P-PHENYLENE DIAMINE AND DIMETHALLYLETHANOLAMINE; SAIDMONOMER MXITURE CONSISTING OF 99.70-99.99 WEIGHT PERCENT OF VINYLCHLORIDE AND, CORRESPONDINLY, 0.30-0.01 WEIGHT PERCENT OF THEPOLY-N-ALLYL SUBSTITUTEED AMINE WHEN THE POLY-N-ALLY SUBSTITUTED AMINECONTAINS 2 JPOLYMERIZABLE TERMINAL ETHYLENIC GROUPS; SAID MONOMERMIXTURE CONSILSTING OF 99.9599.997 WEIGHT PERCENT OF VINYL CHLORIDE AND,CORRESPONDINGLY, 0.05-0.003 WEIGHT PERCENT OF THE POLY-N-ALLYLSUBSTITUTED AMINE WHEN THE POLY-N-ALLYL SUBSITUTED AMINE CONTAINS 3POLYMERIZABLE ETHLENIC GROUPS.